Field
The present invention relates to a sensor arrangement structure.
Description of the Related Art
In the related art, a sensor for the output shaft of an engine is disposed, for example, on a sprocket cover, and this sensor detects the rotational speed or the like of the output shaft.
However, within the sprocket cover, a drive sprocket rotates at a high speed and a driving chain is fed at a high speed, leading to an environment where foreign material, such as dirt, dust, sand, pebbles, or oil, is splattered. It is therefore necessary to prevent the intrusion of foreign material into the sprocket cover because the intrusion of foreign material can cause deterioration in the detection performance of the sensor.
As this technique, in the related art, a configuration is disclosed in which a sensor for detecting the rotational speed of a countershaft is disposed within the sprocket cover that covers the drive sprocket of the countershaft. See, for example, Japanese Patent Publication JP-A No. Hei 08-262049 (Patent Literature 1).
In Patent Literature 1, the sensor is disposed in a space surrounded by the sprocket cover, a cylindrical portion, and a lid member so as to prevent the intrusion of foreign material into the periphery of the sensor. However, in the configuration disclosed in the Patent Literature 1, in case of intrusion of foreign material into the periphery of the sensor, the foreign material cannot be removed, and a structure for more effectively preventing the intrusion of foreign material into the periphery of the sensor has been desired.